Implement Azure Files backend

Co-authored-by: moongdal <moongdal@tutanota.com>

backend/azurefiles/azurefiles_test.go

@@ -0,0 +1,15 @@
+package azurefiles
+
+import (
+	"testing"
+
+	"github.com/rclone/rclone/fstest/fstests"
+)
+
+func TestIntegration(t *testing.T) {
+	var objPtr *Object
+	fstests.Run(t, &fstests.Opt{
+		RemoteName: "TestAzureFiles:",
+		NilObject:  objPtr,
+	})
+}